If that's the case, I would consider it a bug. Please feel free to report it. In general, hyperfine should not take longer than ~3 seconds, unless the command itself takes > 300 ms second to run. In the latter case, we do a minimum of 10 runs by default. So if your program takes 3 min for a single iteration, it would take 30 min by default — yes. But this can be controlled using the `-m`/`--min-runs` option. You can also specify the exact amount of runs using `-r`/`--runs`, if you prefer that.

> I could not find a good way to get Hyperfine to do what I wanted

This is all documented here: https://github.com/sharkdp/hyperfine/tree/master?tab=readme-... under "Basic benchmarks". The options to control the amount of runs are also listed in `hyperfine --help` and in the man page. Please let us know if you think we can improve the documentation / discovery of those options.

I've been using it for about four or five years, and never experienced this behavior.

Current defaults: "By default, it will perform at least 10 benchmarking runs and measure for at least 3 seconds." If your program takes 1s to run, it should take 10 seconds to benchmark.

Is it possible that your program was waiting for input that never came? One "gotcha" is that it expects each argument to be a full program, so if you ran `hyperfine ./a.out input.txt`, it will first bench a.out with no args, then try to bench input.txt (which will fail). If a.out reads from stdin when no argument is given, then it would hang forever, and I can see why you'd give up after a half hour.

> Is it possible that your program was waiting for input that never came?

We do close stdin to prevent this. So you can benchmark `cat`, for example, and it works just fine.

Oh, my bad! Thank you for the correction, and for all your work making hyperfine.